IncidenceIncidence: originally very high (50% of exposed subjects) when enzymes were first used commercially. Current risk is strongly linked to working conditions. The allergic response is caused by the protein structure. The enzymatic activity is responsible for acute symptoms. IgE-depedent mechanism. Symptoms may appear within days or years of the initial contact. Atopic subjects are more prone to sensitization (7 out of 10 cases). Non-atopic subjects may become sensitized (3 out of 10).

ConditionsThe number of enzymes being used in industry is steadily increasing. In a study performed in 1977, the frequency of sensitization was 8 out of 10 cases for trypsin, 8 out of 10 for chymotrypsin, 7 out of 10 for bromelin and lower for amylase (3 out of 10) and lipase (3 out of 10). These data were collected by the pharmaceutical industry. The enzymes are additives which are also used in preparation of animal foods; a case of occupational asthma was reported in 2001 in a factory preparing these foodstuffs. In the detergent industry, the Bacillus subtilus enzyme has been implicated since the 1960s. The industry eliminated this enzyme and replaced it by encapsulated enzymes in the 1970s. Amongst these, an amylase derived form Bacillus licheniformis is frequently used. Four cases of asthma caused by this encapsulated enzyme have now been reported. Thus, encapsulation alone is insufficient to eliminate the risk of this occupational asthma.